"We expect for there to be further earthquakes in the region, some of which may be widely felt. This is the largest earthquake in the region since an M6.2 on March 6," GeoNet tweeted.
The National Emergency Management Agency said there was no threat of tsunami.
People as far afield as Auckland and the South Island reported feeling it.
A resident of Ōhope in the eastern Bay of Plenty said she felt shaking and her light shades were swinging.
Another person camping in the area described it as a "freaky feeling".
"We are camping in Ōhope and my friend and I felt our chairs sway side to side," Shara said.
"We knew it must be an earthquake. What a freaky feeling."